The monitoring of a patient's vital signs is one of the most fundamental aspects of proper patient care. Vital signs such as body temperature, heart rate, respiration rate, and blood pressure are routinely determined and monitored by health care providers. In a hospital or other emergency care setting, vital sign monitoring is typically done on a continual basis, at least in relatively more developed regions of the world. When one or more vital signs begin to degrade, the speed at which attending health care providers are able to be notified and react can be the difference between life and death of the patient.
Typically, vital sign monitors are constructed as bedside devices attached to hospital beds or carts, or are integrally built into the walls of a facility room. Usually, these devices are powered through standard wall outlets (mains electricity). The utility of such devices is substantially reduced in areas where mains electricity is unavailable, insufficient, or unreliable, such as in developing nations, in certain emergency situations, in remote locations, and in war zones, for example. Further, the typically large and clunky construction of such devices limits their usefulness in circumstances where space is a concern. Additionally, conventional vital sign monitors are relatively costly, making them difficult to obtain and use in many situations where they could otherwise benefit patient care and improve outcomes.